The present invention relates to a portable handheld terminal. More particularly, the present invention relates to a portable handheld terminal having integrated keypad, display, and optical bar code reader functions and further including electromagnetic transceiver means for wire less transmission of data to and from a base communications station. Additionally, the present invention relates to a portable handheld terminal having a novel handle design which facilitates ease of use.
There are portable bar code readers available on the market which provide for the collection of data for later downloading at a computer terminal. An example of such a bar code reader is one used to take inventory. The bar code reader will typically include memory for storage of the inventory data and a communications port for later downloading of the inventory data at the computer terminal. Such bar code readers do not provide for interactive functioning with a computer system in full duplex fashion, i.e., enabling communication to and from the computer system. Some bar code readers have been installed as a part of a microcomputer, e.g., by addition of a printed circuit board in one of the microcomputer's available slots. While this provides a bar code reader which can interactively communicate with the microcomputer, it does not provide for a bar code reader which is readily portable and can be hand carried by the user to the application site wherein the interactive processing and collection of data is to occur. The bar code reader is physically wired or interconnected to the microcomputer and while the terminal may indeed be somewhat transportable from one location to another, it is not intended for hand carried use. Typical use of such a bar code reader and microcomputer arrangement might be that of a retail store such as a grocery store wherein items are being sold at a checkout counter.
Additionally, many bar code readers are not used in conjunction with integrated keyboard and display functions wherein the user can control operation of the bar code reader by use of the keyboard and wireless interactive communication with a main computer system.
In bar code reading, a light source is typically used to illuminate a bar code, which is a series of printed bars of various widths and spacing. An optical detector "reads" the reflections from the bars and identifies them as a code or number. A typical example of this technique is found at supermarkets, where a product's bar code is scanned and billed as it passes over the bar code reader at the checkout counter. During the bar code reading process, the bar code is "scanned" by causing relative movement between the bar code and the bar code reader. The bar code reader might be moved relative to the bar code, or the bar code might be moved relative to the bar code reader. The "scanning" of the bar code is necessary since the optical detector has a very limited range of detection along the X-axis or direction of movement or "scanning".
Two types of optical technologies often used in bar code readers are the light emitting diode (LED) and the laser. Because of their lower costs, relatively low power requirements, and safety, LEDs are more commonly used. However, due to the fact that LEDs emit a relatively low light level, bar code readers using LEDs must be held closer to the bar code and are often referred to as "contact" bar code readers. Contact bar code readers will typically use a bar code wand which is held in contact with the bar code and then move relative to the bar code. Lasers emit a higher level of light, and thus bar code readers using such technology can scan a bar code without making contact with the bar code. These bar code readers are often referred to as "non-contact" bar code readers.
Contact bar code readers are difficult to use on other than flat surfaces. Non-contact bar code readers are rather focal specific and require a rather uniform scan rate and uniform distance between the bar code and the optical detector of the bar code reader. In addition, lasers can present health risk and may be unsafe for use in various industries, particularly the health care industry. Also, lasers consume relatively more power and are relatively expensive when compared to LEDs.
The present invention solves these and many other problems associated with currently existing bar code readers.